Drivers are increasingly required to interact with electrically transmitted audible signals, particularly speech, such as with a mobile telephone or with systems for navigation, information, and entertainment.
It would be beneficial if the interactive audible signals were to sound as coming from a source in front of the driver, rather than from the side or rear. In this manner, it would feel more natural for the driver to interactively respond by speaking in a forward direction toward the perceived source of the audible signals, without turning the head. In most vehicles, however, there is no provision for locating a loudspeaker in front of the driver—audible signals must physically originate from loudspeakers in other locations. It is desirable, therefore, to have a method for electronically altering the signals prior to input to the loudspeakers in order to simulate a virtual sound source in front of the driver, taking into account the location of the driver's head and the acoustical characteristics of the vehicle's interior. This goal is met by the present invention.